Projection of asymmetric boundary shifts along latitude gradient for Chinese trees under climate change

Climate change is causing widespread boundary shifts of terrestrial plants. However, current works mainly focus on leading edges, but seldom takes a comparative study of trailing and leading edge shifts. Here, the shifts of Chinese trees were simulated along the leading and trailing edges under the maximum representative concentration path (RCP8.5). The results show that Chinese trees likely exhibit a variety of asymmetric boundary shift pattern. Synchronous northward (62.7%) dominant the trade off shift between leading and trailing edge and temperature factors have a significant positive correlation with the boundary shift distance. The other 37.3% species show a southward shift for one or two edges and this pattern could be mainly the comprehensive interaction of heat, low temperature, available water and topographic factors. The study suggest that simple view of polarward shift for leading and trailing edges is not suitable for the explanation of tree migration in China.

气候变化正导致陆生植物（terrestrial plants）的分布范围边界发生广泛偏移。然而，现有研究多聚焦于分布前沿（leading edge）的偏移，极少开展分布前沿与分布后沿（trailing edge）偏移的对比研究。本研究针对中国境内的树木，在最大典型浓度路径（RCP8.5）情景下，模拟了其分布前沿与后沿的偏移情况。研究结果显示，中国树木大概率呈现出多种不对称的分布边界偏移模式：其中同步向北偏移的物种占比达62.7%，为前沿与后沿偏移权衡中的主导模式，且温度因子与分布边界偏移距离呈显著正相关；剩余37.3%的物种则存在单个或两个分布边界向南偏移的情况，这类模式主要由热量、低温、可利用水分与地形因子的综合交互作用所导致。本研究表明，仅以“前沿与后沿均向极地偏移”的简单视角，无法合理解释中国境内的树木迁移现象。